1. Field of the Invention
The present invention relates to an endoscope apparatus that performs fluorescence imaging and a method for controlling a fluorescence imaging apparatus.
2. Description of the Related Art
An endoscope apparatus which uses an endoscope has been widely used in a medical field. A light source apparatus of a conventional endoscope has generally adopted a scheme to attain the irradiation with a desired light from a white color light source such as a xenon lamp and a halogen lamp through a band-pass filter.
In recent years, inexpensive and high-output solid light-emitting devices such as a light emitting diode (abbreviated as LED) and a semiconductor laser have been put into practical use, and a light source apparatus or an illuminating apparatus made of a combination of a plurality of light-emitting devices, for an endoscope, has been used.
Such a light source apparatus can advantageously control a quantity of light for each wavelength independently. However, disadvantageously, in the case where an image is obtained or generated by means of illumination by a plurality of light-emitting devices, or a plurality of images are displayed superimposed on one another, if a light quantity ratio of the plurality of light-emitting devices is not controlled to be constant, the balance and the like of an obtained image may be distorted.
In particular, in the case where an image of fluorescence (a fluorescence image) and an image of a reflected light of a reference light (a reflected image) are superimposed on one another or the like to display the images at the same time, if the intensities of both the images are substantially different, it is also desired that the light quantity ratio be controlled to be constant.
In order to address such a case, for example, in a conventional example disclosed in Japanese Patent Application Laid-Open Publication No. 2008-259595, an intensity control portion controls a relative intensity of illuminating light components with respect to excitation light components depending on the luminance value of observation image data from a fluorescence image and a reflected image of a subject, and adjusts the balance of the reflected image with respect to the fluorescence image.